Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden and does well: it discloses that oversized PDFs are skipped, that text length is capped by default, and that failure (success=False) occurs for too-large, image-based, or unreadable files. It stops short of mentioning network/auth requirements, rate limits, or download behavior, leaving some gaps for a network-and-parse operation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.